#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
#define rep(i, a, b) for (int i = (a); i <= (b); i++)
#define per(i, a, b) for (int i = (a); i >= (b); i--)
#define endl '\n'
const int N = 2e5 + 5;

int n, m;
int a[N];
int gcd(int a, int b) { return !b ? a : gcd(b, a % b); }
int main() {
  ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);
  int ans = 0;
  cin >> n;
  rep(i, 1, n) {
    int x;
    cin >> x;
    if (x < 0) x = -x;
    ans = gcd(x, ans);
  }
  cout << ans;
  return 0;
}